1. PUAN ROSDALILA ROSLAN AHF 2203

3. Overview  The basic faculties required to be able to successfully pilot an aircraft include adequate and unimpaired senses of vision and hearing, sufficient intelligence and judgement, suitable personality, and motor skills.

4. Overview  When flying, the pilot is exposed to additional factors such as the hypoxia, high noise levels, the requirement for radio communication with the outside world, higher accelerations during aircraft maneuvering, and visual- vestibular illusions.

5. Overview  The ingestion of alcohol influences virtually every system in the human body in some way or another.  The most readily apparent effects of alcohol are usually a result of its effect on our central nervous system.  The effect of alcohol most pertinent to aviation is its impairment of a variety of central nervous system functions.

6. Overview  The metabolism of all other body systems is altered. Included is the gastro-intestinal tract, the liver and pancreas, muscles, the blood, the heart, the immune system, the respiratory system and electrolyte balance,

8. Why we have to avoid alcohol?  United States the percentage of pilots with elevated blood alcohol levels involved in fatal general aviation accidents during the early 1960s was approximately 43%. This proportion had fallen somewhat, but remained between 15% and 20% during the 1970s.  In recent times, aircraft accidents has tended to remain at the 10% - 30% level.

9. Why we have to avoid alcohol?  “blood alcohol concentrations of 0.04% are associated with substantial and highly significant increases in the number and potential seriousness of procedural errors committed by both inexperienced and highly experienced pilots”.

11. Effects of alcohol  Impairment of higher cortical functions.  The effects of alcohol on visual and visual-vestibular function.  Spatial orientation.  Impairment of motor skills.  Effects in conjunction with altitude hypoxia.  Tolerance to positive radial acceleration.  Hangover effect.

13. Impairment of higher cortical functions.  There are specific areas involved such vision, hearing, touch, movement, and smell including other areas which are critical for thinking and reasoning.  Blood alcohol levels as low as 0.027% cause a decrease in visual tracking performance during whole body motion and in non-moving individuals.  Alcohol disrupts the laying down of memory with a likely subsequent reduction in aviation safety.

14. Impairment of higher cortical functions.  Reaction times to different stimuli have been shown to be increased by alcohol ingestion.  The monitoring and decision components of reaction time tasks are also impaired by alcohol levels of 0.09%.  All of these functions play an important role in the safe piloting of aircraft. Impairment of any of these functions will be detrimental to flight safety.

16. The effects of alcohol on visual and visual-vestibular function  The sense of vision is required for spatial orientation and navigation during both ‘visual’ and ‘meteorological’ flight conditions as well as the monitoring and adjustment of aircraft performance.  Any impairment of the sense of vision, therefore, has the potential of adversely influencing flight performance and flying safety.

17. The effects of alcohol on visual and visual-vestibular function  The speed of the eyes, in pursuing a target, is reduced by alcohol.  Similarly the speed of the eye’s saccadic motion, their latency times, and reaction times are impaired by blood alcohol concentrations in excess of 0.04%.  Double vision and dilatation of the pupils, resulting in blurred vision, can also result from alcohol intoxication.

18. The effects of alcohol on visual and visual-vestibular function  Blood alcohol levels of 0.05% and above have been shown to slow the ability of the eyes to accommodate or adjust their focus.  During the angular accelerations of flight there occur reflex rapid, oscillatory eye movements called nystagmus which tend to impair the view of objects within the aircraft.  This can result in blurring of vision of instruments and a subsequent impairment of performance.

19. The effects of alcohol on visual and visual-vestibular function  Alcohol ingestion, and low light levels, impair the ability to suppress this nystagmus.  Impairment occurs at blood alcohol levels as low as 0.02%.

20. The effects of alcohol on visual and visual-vestibular function  Another condition, called Positional Alcohol Nystagmus results oscillatory eye movements when the head is placed in specific positions in the absence of angular acceleration which may lead to impairment of vision.  Alcohol has little direct effect on visual acuity and the information concerning its effects on colour vision is conflicting.

22. Spatial orientation  lead to loss of control of the aircraft and an accident will result unless control is regained.  Maintaining orientation depends primarily on vision but the vestibular apparatus organs also contribute.  The function of the vestibular apparatus, and its interaction with the eyes in maintaining correct posture and balance is impaired by alcohol.

23. Spatial orientation  High doses of alcohol retard the suppression of post-rotatory nystagmus, an important consideration in turning aircraft.  Impairment, by alcohol or any other agent, of the visual system and the intimately related vestibular system would cause some degree of pilot incapacitation, and could lead to spatial disorientation and an aircraft accident.

25. Impairment of motor skills  While alcohol has little effect on muscular strength it impairs the coordination of motor functions.  Basic motor coordination tasks such as standing still, hand steadiness, walking, especially with the eyes closed, and a variety of sensorimotor tracking/pointing tasks are all impaired by alcohol

27. Effects in conjunction with altitude hypoxia  It has been traditionally considered that alcohol and altitude hypoxia had a synergistic effect on performance impairment

29. Tolerance to positive radial acceleration  In performing a balanced turn in an aircraft the pilot is exposed to a centrifugal force due to the radial acceleration.  This acceleration results in an increase in his weight.  High levels of this acceleration can result in impairment of vision and even unconsciousness as blood is unable to reach the eyes and brain.

30. Tolerance to positive radial acceleration  Ingestion of alcohol reduces the tolerance of this acceleration.  A ‘moderate’ dose will reduce the threshold by 0.1 - 0.4 G (‘G’ = Unit of Gravitational Acceleration) and will intensify the severity of the symptoms produced by a given level of acceleration.

32. Hangover effect  Symptoms commonly associated with a hangover are headache, dizziness, dry mouth, stuffy nose, fatigue, upset stomach, irritability, impaired judgment, and increased sensitivity to bright light.